darwintrace: fix disabling the sandbox, continue searching if dependency check fails
darwintrace: fix disabling the sandbox, continue searching if dependency check fails

Disabling the sandbox means the filemap contains a single entry allowing '/'.
This previously failed with the new __dt_pathbeginswith function.

If a dependency check previously failed, the file was considered inaccessible.
However, there might be situations, where the filemap contains further entries
allowing access.

git-svn-id: 620571fa9b4bd0cbce9a0cf901e91ef896adbf27@107551 d073be05-634f-4543-b044-5fe20cf6d1d6

danchr/macports-base,danchr/macports-base,macports/macports-base,neverpanic/macports-base,neverpanic/macports-base,macports/macports-base